The invention relates to an atomizing or dosing pump with an outlet valve, an outlet passage positioned downstream thereof and which terminates in a mouthpiece in the form of an opening or an atomizing nozzle, and an additional closure member arranged in the outlet passage.
German Pat. No. 21 62 514 discloses a hand pump more particularly intended for dispensing creamy or pasty media and which has a single-acting thrust piston pump like the piston pumps used for perfume atomizers. The outlet valve is provided at the outlet side end of the hollow piston rod, with which is associated a device for sucking back into an intermediate reservoir medium present in the outlet passage following on to the valve after the end of the delivery stroke, in order to prevent hardening taking place at the outlet nozzle. Between said reservoir and the outlet passage is provided a closure member in the form of a slotted disk, which can open to either side and brings about a partial closure as a result of its natural elasticity.
In addition, British Pat. No. 1 366 774 discloses an atomizing pump, whose outlet valve has a double closing or sealing function in that on the one hand under internal pressure it rises axially from a valve disk and on the other hand by radial expansion of a hose-like portion of the same piston section frees a cross hole in the piston rod. However, as the second valve is a long way from the actual discharge opening or the atomizing nozzle, influencing of the medium in the flow direction behind the outlet nozzle cannot be excluded.